The drilling rig， as an important ground equipment in drilling engineering， is undoubtedly a drilling weapon. The full hydraulic core drill is the main developed direction of the coring rig. This article introduces the main functions of core drill in providing pressure and rotational motion during rock breaking from the perspective of popular science. The working principle of hydraulic transmission is analyzed by analogy with lever priciple. The development process from vertical axis handlebar drilling rigs， vertical axis hydraulic drilling rigs to fully hydraulic core drilling rigs is reviewed， the characteristics of lightweight core drill and their advantages in meeting green exploration requirements are elaborated， and the development direction of fully hydraulic core drill is put forward， which is intelligence， efficiency and greening.